Kohl's - The department store chain posted lower-than-expected earnings and forecast full-year profit that missed Wall Street estimates. The company also said it expects same-store sales to be between flat to up 2 percent this year.

Groupon - Groupon was downgraded to "underperform" from "neutral" by at least two brokerages, and to "market perform" from "outperform" at Wells Fargo a day after the deal-a-day website posted earnings that missed estimates on revenue of $638 million, in line with expectations. The company also handed in current-quarter earnings guidance that widely missed Wall Street projections.

EBay - BMO initiated coverage of the online auction company with an "outperform" rating.

Boston Beer - The maker of Samuel Adams beer was downgraded to "perform/hold" from "outperform/buy" at Williams Financial Group, but the brokerage raised its price target to $160 from $130.

Vitamin Shoppe - The nutritional supplements retailer was downgraded to "neutral" from "buy" at Bank of America/Merrill Lynch.

Molycorp - The rare earth producer said it is delaying its quarterly results and its annual report, citing it's struggle to determine the size of a goodwill impairment charge that it must take in the fourth quarter.